Many game systems have been proposed in which game pieces are held to a game board magnetically so that the position of the pieces on the board will not be accidently disturbed. This has been done, for example, by providing a magnetic substance in the pieces and a magnetically attractable substance in the board. Generally, a layer of foil or particles such as iron filings are sandwiched between adjacent layers of the board. The magnetic layer may be formed by a variety of methods, including sieve printing or silk screening. See, for example, Holtz U.S. Pat. No. 3,093,919, issued June 18, 1963, and Green U.K. Patent App. No. 2,150,842, published July 10, 1985. In the alternative, discrete spots on the board containing the magnetically attractable material may be formed by disposing the material in spaced-apart slots or recesses formed in the backing of the board. See, e.g., Szuch U.S. Pat. No. 3,619,313, issued Nov. 9, 1971, and Skelton U.S. Pat. No. 4,049,275, issued Sept. 20, 1977.
The board for such game systems generally includes a support or backing layer, such as cardboard, on which the magnetic layer is disposed, and a covering layer such as paper glued over the magnetic layer. The magnetically attractable material, such as iron oxide particles, may be dispersed in an adhesive binder. See, Holtz, noted above, and Roberts PCT App. No. WO 85/00528.
Such constructions have proven useful in providing "lap top" games, but nonetheless have certain disadvantages. Use of metal foil in such boards is expensive and potentially dangerous, insofar as the sharp foil edges can come loose if the board is damaged. Loose iron filings disposed in recesses tend to settle unevenly, leak out, and rust. Rusting is also a problem with iron particles which are poured onto a layer of adhesive, nor is the problem necessarily solved by distibuting the particles in a conventional adhesive. Such adhesive layers may also lack flexibility, so that the magnetic layer cracks when the board is bent. Finally, providing a magnetically attractable layer over the entire board is usually wasteful because the game pieces need to adhere only to certain areas of the board surface. The present invention addresses these problems.